Rough and finish honing tool



Feb. 24, 1970 'R'iC'LENGLE 3,496,678

' v120mm m r'nusa momma-floor.

Filed Jan. 21, 1965 .5 Sheets-Sheet- 1 INVENTOR ROBER T C. ENGLE BY.[90m 6 PM A T TORNEYS Fb. 24, 1970 c, ENGLE 3,496,678

. ROUGH Am) FINISH noume roor Filed Jan. 21,1965 v I .5 Sheets-Sheet 2-FIG. 2

' .lNl/ENTOR ROBERT 31; ENGLE ATTORNEYS R. C. ENGLE ROUGH ANDFINISH'HONING TOOL Feb. 24, 1970 .5 Sheets-Sheet. 5

Filed Jan. 21, 1965 PIC-3.5

. INVENTIOR ROBERT c, ENGLEZ @owvo A T TORNEYS j R. c. EN'G'LE 3,496,678

.5 Sheets-Sheet 4 I FIG.9

FIGJO U 3 5 w w Feb. 24, 1970 v I Roufi AND FINISH 1101mm TOOL FiledJan; 21, 1965 FIG 1| ATTORNEYS 'Feb. 24, 1970 R. c. ENGLE ROUGH ANDFINISHHONING TOOL .5 Sheets-Sheet 5 Filed Jan. 21, 1965 FIG.I4

FIGJZ 8 M M 7/6! v EVA INVENTOR ROBERT C. ENGLE A T TORNE Y5 UnitedStates Patent US. Cl. 5134 9 Claims ABSTRACT OF THE DISCLOSURE A honingtool having a bladed cone means mounted within the honing tool body,whereby movement of the cone means determines the expansion of a desiredset of either rough abrasive honing stones or finish abrasive honingstones.

This invention relates to a unitary rough and finish honing tool, andespecially for automatically or manually adjusting the position of thecone assembly to effect radial movement either of the rough honingstones or the finish honing stones.

The principal object of this invention is to provide a honing tool whichwill first expand and rotate the rough honing stones for a short periodof time, retract the rough honing stones, then expand the finish honingstones until a preselected finish has been effected.

The object of this invention is to provide rough and finish honing withthe use of one tool per bore in an integrated cycle.

Another object of this invention is to provide roughing and finishing acylinder bore by first expanding coarse grit stones for high stockremoval, and following, expanding fine grit stones for final bore size,finish and geometry.

Other objects, features and advantages become apparent from thefollowing description taken in conjunction with the drawings, wherein:

FIG. 1 is a front elevational view of multiple spindle honing machine,

FIG. 2 is a cross-sectional view of one of the honing tools shown inFIG. 1,

FIG. 3 is a cross-sectional view taken along line 33 of FIG. 2,

FIG. 4 is a cross-sectional view taken along line 44 of FIG. 2,

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 2,

FIG. 6 is a cross-sectional view taken along line 66 of FIG. 2,

FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 2,

FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 2,showing the honing stones in retracted position,

FIG. 9 is a cross-sectional view of the honing tool, showing one stoneexpanded by the cone and blade and the other stone being in itsretracted position,

FIG. 10 is a cross-sectional view of the honing tool taken along line1010, showing one set of honing stones expanded while the other setremains unexpanded,

FIG. 11 is a modification of the honing tool showing the honing stonesbeing expandable by vertically adjusting the cone rod,

FIG. 12 is a front elevational view of another modification of the conerod adjustment,

FIG. 13 is a cross-sectional View taken along line 1313 of FIG. 12.

FIGS. 14 and 15 are cross-sectional views taken along lines 1414 and1515, respectively, and

FIG. 16 is a front elevational view of a further modification of thecone adjusting mechanism.

Previously rough and finish honing with two machines 3,496,678 PatentedFeb. 24, 1970 ice was the accepted way to hone cylinder block bores.Next, improvements in honing equipment made it possible to do asatisfactory job with only one honing operation. As the. cylinder borewalls got thinner and thinner, it became necessary to use softer stonesand longer cycles to get the required accuracy of core size, finish andgeometry. This type of operation increased the cost of honing to a pointwhere many companies tried to limit the stock left by controllingprevious grinding operation more closely. In a few cases, the automaticsize control equipment was removed and time cycle or stroke honing wassubstituted.

Other honing tools included rough honing stones underneath a set offinish honing stones on the same shaft, and the finish honing wouldfollow the rough honing by moving theshaft vertically; however, thisbecame unfeasable for certain type of bores with bore lengthrestrictions.

To overcome this difliculty, special honing tools have been developedwhich contain both roughing and finishing abrasive sticks, designed sothat only one set is expanded at one time. The expansion is accomplishedby several ways; by reverse direction of spindle rotation, by verticalmovement of the cone push rod, or by manual adjustment whichautomatically presets the spindle blades. The preferred embodiment beingthe reversal of spindle rotation. The change in tool rotationaldirection presets a mechanism in the tool so that the finishing stoneswill be expanded as the feed rate is applied. As the bore size isreached, the finishing stones collapse, after which the tools are liftedout of the bore. This change is done automatically and occurs within atime limit of a few seconds.

The special tool, containing both roughand finishhoning sticks,automatically expands either group (depending on the direction of thetools rotation) at predetermined feed rates. Rotating clockwise duringthe roughing cycle, the tool collapses its set of roughing stones assoon as preliminary bore size is reached. Immediately, the rotation ofthe tool is reversed and the tool begins expanding the finishing set ofabrasives. Automatic sizing takes place in both the roughing andfinishing sequences, and incorporates bore gauging devices of the typedisclosed and patented in US. Patents 3,059,- 381, issued Oct. 23, 1962,2,821,049, issued Jan. 28, 1958, and 2,284,325, issued May 26, 1942.

The switchover from the roughing to the finishing sequence is immediate,that is, without an interruption in the tools reciprocation, or the needto withdraw the tool from the workpiece. Initial expansion of theabrasives (in both roughing and finishing sequences) is rapid until thestones touch the work surface. At this instant, the expansion becomescontrolled by the regular feed mechanism at pre-set roughing orfinishing rates, respectively.

This invention is directed to a method of applying rough and finishhoning on a single machine, incorporating automatic size control, whichis shown by Patents Nos. 2,284,325 issued May 26, 1942; 2,777,257 issuedIan. 15, 1957; 2,777,321 issued Jan. 15, 1957; 2,821,049 issued Jan. 28,1958; 3,059,381 issued Oct. 23, 1962. The honing tool is exemplified byPatents 2,383,657 issued Aug. 28, 1945, and 2,998,682 issued Sept. 5,1961.

Referring now to the drawings, FIG. 1 shows an abrading machine 1,having a base 2, on which columns 3 are securely mounted thereon. Thecolumns extend upwardly with a crosshead 4 mounted at the top. Strokecylinders 5, mounted on the crosshead 4, extend downwardly toreciprocate spindle head or carriage 6, which houses the spindle drivemechanism. The spindle drive mechanism controls the rotating drive tothe honing tools '8. Guide bars 7 maintain the spindle head 6 in properalignment with the cylinder bores 10 of the workpiece 9. A pneumaticline 11 extends rearwardly of the honing tools and is connected with afriction device 12, the purpose of which will be hereinafter described.FIG. 2 shows a sectional view of the honing tool 8 and illustrates thepreferred embodiment of the invention. Honing tool 8.is connected totool spindle '97 and, therefore, adapted to be drivingly connected tothe rotating drive source (not shown) of the spindle drive mechanism.The tool spindle, therefore, is adapted for rotation about alongitudinally extending axis thereof and within a generally cylindricalbore 10 of the workpiece 9. Honing tool 8 is connected to the spindle 97by conventional means, as by threaded bolts 13 which mount the outersleeve 14, thereby providing for removal of the entire honing tool 8from the spindle head. The vertical push rod 15 extending through thespindle head 6 has at its lower end a quick disconnect T-connector 16which fits into T-slot recess 17 of center pivotal plug 18. Movement ofthe vertical push rod causes the expansion of the honing stones in amanner as will be hereinafter described. Vertical movement of push rod15 moves center pivotal plug 18 with respect to outer sleeve 14. Thecenter pivotal plug 18 has a vertical recess 19, in which one end of pin20 extending through the outer sleeve 14, slides therein. As shown inFIG. 7, pin 20 slides horizontally a limited distance in opening 21 ofouter sleeve 14, but is retained in horizontal position by a threadedretaining screw 22 in circular opening 23 of ring 24 (see FIG. 2).

To effect slidable movement of ring 24, and thereby select the properhoning stones to be expanded, a friction device 12 is mounted on thecarriage 6. Shown in FIG. 7, friction device 12 consists of a block 25which houses a friction shoe 26 slidable in block 25 and includes anouter curved surface which abuts the outer curved surface of the ring24. The friction shoe 26 is retained in block 25 by an enlarged end 27and restrained by spring 28. It is apparent that fluid pressure throughpneumatic line 11 will enter recess 29 through port 30, causing thefriction shoe to move and frictionally engage the outer ring 24 in amanner and for the purpose which will be described hereinafter.

As shown in FIG. 2, vertical movement of push rod 15 slides the centerpivotal plug 18 vertically within the outer sleeve 14 for the purpose ofexpanding the honing stones against the surface of the bore by thefollowing structural means. A cone push rod 31 is fitted into recess 32of center pivotal plug 18 and is retained therein by pin 33. Cone pushrod 31 extends downwardly and terminates in a smaller diameter portion34. The junction between the smaller diameter portion and the largerdiameter portion is connected to the blade orientation plug 35. Theblade orientation plug 35 is vertically slidable in longitudinal bore 36of drive shaft 37. The drive shaft 37 is connected to the outer sleeve14 by means of a universal or trunnion 38 (shown in FIG. 4) in order toprovide for universal movement and thereby effect proper rotation of thehoning stones, irrespective of eccentric geometry of the bore of theworkpiece.

The actuating pressure, is applied by push rod 15, plug 18, cone pushrod 31 and through cone orientation plug 35 expands the proper type ofhoning stones selected by the direction of rotation of the ring 24.

The cone orientation plug 35, as best shown in FIGS. 2 and 3, comprisesa pair of longitudinal recesses or slots 39 and 39', being offset withrespect to each other by an angle of 36 degrees. A cone orientation pin40 extends through an opening 41 of the drive shaft 37 and terminates inone of the slotted recesses or slots 39 and 39'. With the pin 40 ineither of the slotted recesses 39 and 39, either the rough honing stonesor the finish honing stones will be selected for expansion.

To provide for quick removal of only the tool body portion of the honingtool 8, there is provided a universal adapter assembly 41, retained by alock nut 42. The universal adapter assembly 41 comprises an outer shell43 having a pair of diametrically opposite torque pins 44' which fitthrough openings 45 of the outer shell 43 and extend inwardly tomatingly engage the lower portion of the drive shaft 37 by fitting intoarcuate recesses or bayonet slots 46. To positively lock the universaladapter assembly 41 in the honing tool 8, and as best seen in FIG. 6,the adapter assembly is rotated degrees. The push rod moves verticallywith respect to the drive shaft 37 and the outer shell 43 of theuniversal adapter assembly, and therefore must be provided with aseparate but conjunctive positive lock connection. This is accomplishedby providing a vertical thrust pin 47 pressed through an opening 48 ofthe connecting link 49. The thrust pin 47 also moves 90 degrees inarcuate recess or bayonet slot 50 in conjunction with the torque pins topositively lock the tool body portion to the honing tool 8. To maintainthe pin 47 in the slot 50 the pressure of the cone push rod is appliedthrough a spring 57 and a retaining plug 51 having a set screw 52axially connected to the connecting link 49 and movable in axial opening53 of cone orientation plug 35. The retaining plug 51 has a lowershoulder 54 and an upper shoulder 55 which permits limited longitudinaltravel of the connecting link 49. Pin 56, pressed into the wall of thecone orientation plug 35, permits only limited longitudinal travel ofthe retaining plug 51 between the upper and lower shoulder portions 54and 55 respectively. The spring 57 maintains a compressive force on theretaining plug to prevent accidental withdrawal during assembly ordisassembly operations of the honing tool body '66. The other end of theconnecting link 49 has a recess 58 in which one end of a secondconnecting link 59 is fittingly engaged therein and held by a pin 60extending through the first connecting links 49. The lower end of thesecond link 59 has an enlarged portion 61 which fits loosely in axialrecess 62, but is prevented from withdrawal by a narrow restrictedopening 63 in the cone rod holding plug 64. A universal 65 provides foruniversal action of the honing tool body 66 with respect to the honingtool 8. As shown in FIG. 2, the tool body 66 is connected to theuniversal adapter assembly 41 by the universal 65. The universal adapterassembly 4'1 is further connected to the drive shaft 37 which issubsequently connected to the outer sleeve 14 and, thence, to spindle97. Independently thereof, the cone rod shaft 68 of the cone-rodassembly 67 is threadedly fastened to the cone-rod holding plug 64. Theholding plug 64 is thence fastened to the first connecting link 49 bythe second connecting link 59, which is then fastened to the cone-pushrod 31 by means of cone orientation plug 35. The cone-push rod 31 isjoined to push rod 15 by means of center plug 18.

As described above, and as shown in FIG. 2, there is an independentrelationship between the drive shaft means 14, 37 and push rod means 15,31. The push rod controls the expansion and contraction of the honingstones by means of vertical movement within the drive shafts 14, 37 and,consequently, within the tool body 66. The tool body, which is connectedto the spindle head through universals 65 and 38, rotates with thehoning stones 74-74'.

The cone rod assembly comprises a shaft 68 and an expander, the expandercomprising two sets of wedgeshaped expander cams or cone-rod blades 69and 69 separated by longitudinally extending grooves and having inclinedcam surfaces 70 and 70' which engage the inclined cam surfaces 71 and71' respectively of the stone, expanding plates 72. Mounted on theexpanding plates 72 are stone holders 73, see FIG. 8. Mounted withineach stone holder is a honing stone 74 or 74". The honing stones areinterspaced alternately around the cone rod, that is, for example 74,denoting a rough grinding honing stone, 74' denoting a finish grindinghoning stone. Mounted on the tool body 66 are guides 75 which areinterspaced around the periphery of the tool body to prevent abuse tothe honing stoneas it is being inserted and retracted from the bore 10of a workpiece. As shown in FIGS. 8,

9 and 10, the cone surfaces of the wedge-shaped expander cams orcone-rod blades 69 and 69 expand only one set of plates for eachoperation, thereby providing either a rough honing operation or a finishhoning operation. During the actual honing operation, the transfer fromone set of honing stones to the other set is accomplished automaticallywithin a few seconds. As one set of expanded stones completes theinitial honing operation, either through a timed cycle or by manualcontrol, the cone push rod is retracted to its normal position, therebyretracting the one set of honing stones. After the cone orientation plug35 is turned by means of ring 24 either automatically or manually, theother set of honing stones are expanded by vertical movement of the conepush rod. This is accomplished while the tool body is rotating at itsoperational speed. It is, therefore apparent that changing from therough honing operation to the finish honing operation is doneautomatically in a matter of seconds.

For a modification of the combined rough and finish honing tool, FIG. 11shows a modification of the cone rod assembly, showing the similar toolbody 66 having expanding plates 72 with cam surfaces 71 and 71'. Mountedon the expanding plates 72, are holders 73 which contain honing stones74 and 74'. As with the preferred embodiment shown in FIGS. 2 through10, the honing stones are retracted upon return of the cone rod to itsnormal position by means of retaining springs 76. The modification whichwill expand either set of honing stones is directed to the push rod 77with cone rod blades 78 having cam surfaces 79 and 79' to engage thesurfaces 71 and 71', respectively, of the expanding plates for theexpansion of the rough honing stones, for example 74, and having camsurfaces 80 and 80' to engage the surfaces 71 and 71 of the expandingplates for finish honing stones, for example 74'. The expansion ofeither of the honing stones is accomplished by vertical movement of thecone push rod 77. As readily seen from FIG. 11, upward movement of thecone push rod will expand one set of honing stones, and downwardmovement of the cone push rod will effect retraction of these honingstones and expansion of the other set.

FIGS. 12 through 15 show another embodiment of the cone-rod bladeorientation, in which the cone push rod 81 is oriented by manuallymoving the ring 82 when the tool body 84 is stationary. Movement of thering 82 causes pin 83, which extends through slotted opening 86 of thetool body 84 into either of respective vertical orienting slots 85 and85' in the push rod 81, to orient the cone rod blades to either therough honing or finish honing blade position. The circumferential lengthof slot 86 is less than the distance between the center lines of theslots '85 and 85'. As shown in dotted line of FIG. 14, pin 84' extendsinto slotted recess 85 of the cone push rod 31. To provide properorientation of the cone push rod 81 with respect to the tool body 84,and to prevent eccentric or unbalanced forces in movement of the conepush rod, there is provided diametrically opposite to the first pin andslot arrangement, a second pin 87 slidable in either of the verticalslotted recess 88, 88' in the push rod 81. As shown in FIG. 15 in dottedline, pin 87' extends in slotted recess 88' in conjunction with the pin83' extending in slotted recess 85 of the cone push rod shown in FIG.14.

Another embodiment is shown in FIG. 16 in which orientation of the conepush rod 89 with respect to the tool body 90 is accomplished by verticalmovement of the bracket 91. The bracket 91 is connected with an annularwasher 92 in which pin 93 extends therethrough and slides withinS-shaped slot 94 of the tool body 90 and in a vertical slot, not shown,in the cone push rod 89. A rod 95 may be connected by pin 96 to thebracket 91 to provide an extensible handle if, for example, the honingtool stands too high for the operator to reach. The operator can graspthe handle of the rod 95 and move it vertically, either up or down, andthus effect the cone orientation to the desired blade position; however,the rod may be moved by other means, for example, a motor.

The honing stones may be of any suitable type, for example, bondedabrasive consisting of any of the usual abrasives, such as siliconcarbide or aluminum in its various forms, also diamonds, and the bondmay be of any desired type, for example, vitrified ceramic bond,resinoid bond, including nautral and synthetic resins, rubber, or metalbond.

It will be apparent from the foregoing that the invention provides animproved method of honing workpieces which permits the work to befinished precisely to desired dimensions without interrupting the honingoperation; that is, both rough honing and finish honing cycles areaccomplished on the same tool. The improved apparatus is simple andrugged in construction, and yet adapted to provide extremely accuratemeasure of the work size. If desired, gauging apparatus may beincorporated giving a continuous indication of size available,'thusproviding for accurate gauging of a bore or the like during the entireoperation. Moreover, a cylindrical workpiece may be gauged accuratelythroughout its length with a minimum of effort on the part of theoperator and without loss of time. As a matter of convenience, thegauging apparatus may be incorporated directly into the tool, such asdescribed in Patent 2,284,325, issued May 26, 1942.

OPERATION In placing the machine in operation, the work is secured inplace on the work support and limit stops (not shown) are set to definethe desired working stroke of the tools. After the machine has beenpreliminarily set in the above manner, it is started by the operator bypressing the start button (not shown). The spindle head moves downwardlyuntil it reaches the preliminary limit stop when the tools have fullyentered into the work. The honing operation commences when the motor isenergized, thus causing rotation of the honing tool. The cone rod shaftis then moved upwardly to expand first the rough honing stones. Duringthe initial rough honing cycle the tools are traversed repeatedly fromone end of the work to the other. After a preselected time interval inwhich the rough honing stones have removed a portion of the boresurface, the cone rod shaft is lowered, thereby effecting retraction ofthe rough honing stones. At this instant, energization of the valve (notshown) allows pneumatic fluid to effect movement of the friction shoeagainst the cone orientation pin into the other of the two longitusureof the friction shoe sliding against the outer ring causes the outerring to drag behind the outer sleeve when the direction is reversed,thus effectively orienting the cone orientation pin into the other ofthe two longitudinal slots of the orientation plug. While the spindle isnow rotating in the reverse direction, the cone push rod shaft is movedupwardly. Since the cone orientation pin is now sliding in the otherlongitudinal slot of the orientation plug, the finish honing stones willthus be expanded. After a preselected time interval of the finish honingcycle, the cone rod shaft is lowered, thereby rectracing the finishhoning stones. The tools are then raised from the bores of the workpieceby the spindle head in preparation for the next workpiece.

While the invention may be performed in various ways, the preferredembodiment is one in which the expansion from rough to finish honingstones is accomplished by a reverse direction of spindle operation. Thechange in tool rotational direction presets the mechanism in the tool sothat the finishing stones will be expanded after the rough honing stoneshave been applied.

(4) Controlled surface finish (5) Longer stone life (thestock-removal-to-stone-wear factor is improved 20%) (6) Eliminatesdouble handling and/or locating work art p (7) Eliminates need foradditional machine and operator (8) Conserves floor space (9) Makespossible higher production rates (10) Stone change is fast and simple.

The roughing and finishing tool performs very well and demonstrates thefollowing capabiities:

(a? Better bore geometry is obtained with the rough and finish processthan with a standard honing cycle, when each removes stock at the samerate. Roundness accuracies of 0004-0006 are obtained with the rough andfinish tool compared to .00O9.0012 for a single honing cycle (bothremoving stock at the rate of .005 per 30 seconds). Straightness is alsoimproved with the rough and finish tool.

(b) Higher production rates are achieved with the rough-and-finish toolwithout sacrificing geometry. For example, the conventional honing cyclehad to be reduced to a stock removal rate of .0025 in 30 seconds inorder to achieve .0004.0006 roundness accuracies /2 the rate that isobtained with the rough-and-finish tool).

(c) Stone selection is less critical with the rough-andfinish tool.Since free cutting, rough honing stones can be used until the borereaches a predetermined size, the

finishing stones can be selected to remove a constant f tive test of aconventional honing cycle. The volume ratio obtained with the fiveroughing stones was about 58/1, and the five finishing stones wasapproximately 30/1 compared to a ratio of 25/1 for the conventionalcycle when the stock removal rate was set at .005/30 seconds for thecombined rough and finish sequence, as well as the conventional cycle.

It will be apparent from the foregoing that the inven= tion describedprovides a honing tool of novel and advantageous character. The honingtool embodies novel means for expanding a plurality of rough honingstones while effectively maintaining a plurality of finish honing stonesin reserve for the next cycle of operations; mat is, after the roughhoning cycle, the rough honing stones are retracted, and the finishhoning stones are expanded.

It is to be emphasized that various equivalent changes may be made inthe various elements which comprise the device and that these variouselements may be integrated or separated without departing from thespirit of the invention or the scope of the appended claims, so long asthe novel results are attained. In all cases, the drawings anddescriptive material are to be interpreted as illustrative rather thanlimiting, and for a determination of the scope ,of the invention,attention is directed to the appended claims.

What I claim is:

1. A honing machine having, in combination, a hollow rotary body havinga plurality of angularl spaced longitudinal slots, first and second setsof honing elements having abrasive surfaces of different characteristicsdisposed in said slots and alternating with each other around said bodywith said abrasive surfaces facing outwardly for engagement with a borewall to be honed, each of said elements having a follower on its innerside, an expander disposed within and movable axially of said bodythrough a preselected range of feed motion from a first position to asecond position, said expander having a set of angularly spacedwedge-shaped cams selectively alineable with the followers of either setof honing elements and operable upon axial movement of said expander inone direction to feed the aiined set of elements outwardly relative tosaid body, from a collapsed condition in said first position to a fullyexpanded condition in said second position, said cams being separated bylongitudinal grooves for receiving the followers of the other set ofelements during said feed motion, a section on said expander of circularcross-section merging smoothly with the smaller ends of said cams andlevel with the bottoms of said grooves, said followers engaging saidsection when said expander is in said first position, means forselectively turning said expander to bring said cams into alinement withthe followers of either set of honing elements in said first position,and mechanism for moving said expander axially of said body in alinementwith each selected set of elements.

2. A honing machine having, in combination, a hollow rotary body havinga plurality of equally spaced longitudinal slots, first and second setsof honing elements having abrasive surfaces of different characteristicsdisposed in said slots and alternating with each other around said bodywith said abrasive surfaces facing outwardly for engagement with a borewall, an expander disposed within and movable axially of said body andhaving a series of wedge-shaped cams angularly spaced apart forengagement with the inner sides of alternating elements around saidbody, said expander also having a plurality of angularly spacedlongitudinal grooves separating said cams and adapted to be alined withthe inner sides of alternating elements around said body, mechanism forselectively turning said expander in one longitudinal position thereofback and forth between a first angular position in which said cams arealined with the elements of said first set and a second angular positionin which the cams are alined with the elements of said second set, andmeans for moving said expander axially relative to said body in both ofsaid angular positions to feed said elements outwardly relative to saidbody.

3. A honing machine having, in combination, a rotary spindle, a hollowtool body on said spindle having a plurality of angularly spaced radialslots, first and second sets of honing elements having abrasive surfacesof different characteristics disposed in said slots and alternating witheach other around said body, an expansion rod disposed within andreciprocable longitudinally of said spindle, an expander disposed Withinsaid body and movable with said rod, said expander having a plurality ofangularly spaced cams thereon, mechanism for turning said rod and saidexpander selectively between two angularly spaced positions to alinesaid cams selectively with the respective sets of honing elements, andmeans for moving said rod and said expander axially back and forthrelative to said body in each of said positions to control the feedingand retracting of the selected set of honing elements.

4. A honing machine having, in combination, a hollow rotary body havinga plurality of angularly spaced longitudinal slots, first and secondsets of honing elements disposed in said slots and alternating with eachother around said body and having abrasive surfaces of differentcharacteristics facing outwardly for engagement with a bore wall, anexpander disposed within and movable axially of said body and having asingle set of cams spaced angularly apart for engagement with the innersides of each set of honing elements, said cams being operable uponmovement of said expander in one direction to feed the alined set ofelements outwardly relative to said body, means for turning saidexpander selectively between two angularly spaced positions in whichsaid cams are alined with the inner sides of the respective sets ofelements, mechanism for moving said expander axially of said body inboth of said positions to feed the selected set of elements, and meanson said expander for disabling each set of elements when said cams arealined with the other set.

5. In an abrading machine, the combination of, an abrading tool, a pairof spaced abrading elements mounted on said tool for independent feedingand retracting movement, each of said elements having an outer abradingsurface and an inner follower, an expander having a cam selectivelyalineable with either of said followers and shaped to move the alinedfollower outwardly upon movement of the expander in one direction and topermit retraction of the follower upon movement of the expander in theopposite direction, mechanism for selectively moving said cam intoalinement with either of said followers, and means for moving saidexpander back and forth in alinement with each follower to control thefeeding and retracting movement of said elements.

6. A honing machine having, in combination, a hollow rotary body havinga plurality of angularly spaced longitudinal slots, first and secondsets of honing elements disposed in said slots and alternating with eachother around said body with abrasive surfaces facing outwardly forengagement with a bore wall to be honed, an expander disposed withinsaid body and having a set of cams spaced apart for engagement with theinner sides of either set of honing elements, said expander beingmovable relative to said body through a preselected range of motion tofeed said elements outwardly relative to said body, means for bringingsaid cams selectively into operative association with either of saidsets of honing elements by a selecting motion transverse to said feedmotion while disassociating said cams from the other set of honingelements, and mechanism for effecting said feed motion with said cams inoperative association with each set of cams.

7. In an abrading device comprising:

(a) a rotatable honing tool;

(b) said honing tool including an outer sleeve terminating at its lowerend in a honing tool body;

() said honing tool body having a longitudinal opening extendingtherethrough and including longitudinally extending circumferentiallyspaced slots;

(d) a plurality of abrasive honing stones, said honing stones includinga set of rough abrasive honing stones and a set of finish abrasivehoning stones;

(e) a plurality of plates for holding said abrasive honing stones, eachof said plates holding each of said abrasive honing stones extendingthrough said slots and terminating inwardly radially in inclined camsurfaces;

(f) unitary cone means extending within said longitudinal opening ofsaid honing tool body, said unitary cone means includingcircumferentially spaced radially extending wedge-shaped blades;

(g) each of said wedge-shaped blades on said unitary cone means havinginclined cam surfaces engaging corresponding inclined cam surfaces oneach of said plates;

(h) a cone push rod extending longitudinally axially through said outersleeve and honing tool body, and terminating at its lower end at saidunitary cone means, said cone push rod adapted tobe moved longitudinallyaxially within said outer sleeve and honing tool body; and

(i) means for partial rotation of said unitary cone means, relative tosaid honing tool body, whereby partial rotation of said unitary conemeans determines the selective expansion of a desired set of abrasivehoning stones.

8. In an abrading machine, comprising:

(a) a tool support means;

(b) a rotatable honing tool journaled on said tool support means;

(c) said honing tool including an outer sleeve terminating at its lowerend in a honing tool body;

(d) said honing tool body having a longitudinal opening extendingtherethrough and including longitudinally extending circumferentiallyspaced slots;

(e) a plurality of abrasive honing stones, said honing stones includinga set of rough abrasive honing stones and a set of finish abrasivehoning stones;

(f) a plurality of plates for holding said abrasive hon- 1ng stones,each of said plates holding each of said abrasive honing stonesextending through said slots and terminating inwardly radially in coneengaging means;

(g) cone means extending within said longitudinal opening, said conemeans including circumferentially spaced radially extending blades;

(h) said blades having inclined cam surfaces engaging correspondinginclined cam surfaces on said plates;

(1) a cone push rod extending centrally through said outer sleeve andterminating at its lower end at said cone means, said cone means beingentirely within said honing tool body, and said cone push rod adapted tobe moved within said outer sleeve; and

(j) means for moving said cone means, whereby movement of said conemeans determines the expansion of a desired set of abrasive honingstones, said means for moving said cone means comprises:

(1) at least one pair of slotted recesses extending parallel to thelongitudinal axis of said cone push rod; and

(2) a pin extending into said cone push rod and adapted to slide ineither one of said pair of slotted recesses, whereby movement of saidcone push rod determines the expansion of a desired set of abrasivehoning stones.

9. In an abrading machine, comprising:

(a) a tool support means;

(b) a rotatable honing tool journaled on said tool support means;

(0) said honing tool including an outer sleeve terminating at its lowerend in a honing tool body;

(d) said honing tool body having a longitudinal opening extendingtherethrough and including longitudinally extending circumferentiallyspaced slots;

(e) a plurality of abrasive honing stones, said honing stones includinga set of rough abrasive honing stones and a set of finish abrasivehoning stones;

(f) a plurality of plates for holding said abrasive honing stones, eachof said plates holding each of said abrasive honing stones extendingthrough said slots I and terminating inwardly radially in cone engagingmeans;

(g) cone means extending within said longitudinal opening, said conemeans including circumferentially spaced radially extending blades;

(h) said blades having inclined cam surfaces engaging correspondinginclined cam surfaces on said plates;

(i) a cone push rod extending centrally through said outer sleeve andterminating at its lower end at said cone means, said cone means beingentirely within said honing tool body, and said cone push rod adapted tobe moved within said outer sleeve; and

(j) means for moving said cone means, whereby movement of said conemeans determines the expansion of a desired set of abrasive honingstones, said means for moving said cone comprises:

(1) an S-shaped slot in said tool body;

(2) an annular ring around said tool body;

(3) a pin extending through said slot and into said cone push rod,connected to said annular ring; and

(4) a bracket connected to said annular ring whereby movement of saidbracket causes movement of said pin to slide in said S-shaped slot 11 12and effect movement of said cone and determine 2,790,278 4/ 1957 Smith51346 the expansion of a desired set of abrasive honing 2,805,521 9/1957Hasty 51338 stones. 3,013,363 12/1961 Swanson 51-34 References CitedUNITED STATES PATENTS 5 FOREIGN PTENTS 67,758 8/1939 Johnson 51-343212727 8/1956 Austraha' 2,229,318 1/1941 Wallace 51-34.3 2,263,78111/1941 Kline 51 342 JAMES L. J NES, P y E r 2,284,325 5/1942 Kline 513CL 2,383,657 8/1945 Klein s1344 51444, 346 2,443,268 6/1948 Palotsee51344

